A mechanoreceptor cell located in the inner ear that is sensitive to auditory stimuli. The accessory sensory structures are arranged so that appropriate stimuli cause movement of the hair-like projections (stereocilia and kinocilia) which relay the information centrally in the nervous system.

A bundle of cross-linked stereocilia, arranged around a kinocilium on the apical surface of a sensory hair cell (e.g. a neuromast, auditory or vestibular hair cell). Stereocilium bundles act as mechanosensory organelles by responding to fluid motion or fluid pressure changes.